Process of making rubber articles.



1N0. 852,130. PATENTED APR. 30, 1907.

P. A. MAGOWAN.

BROCESS OF MAKING RUBBER ARTICLES. APPLICATION FILED APB.20,1906.

FRANK A. MAGOWAN,

OF NEW YORK, N. Y.

PHOCESS OF' MAKING RUBBER ARTICLES- Specification of Letters Batent.

Patented April 30, 1907.

Application filed April 20,1906. Serial No. 312,834.

To all whom it may concern.-

Be it known that I, FRANK A. MAoowAN, a citizen of the United States, residing in the borough of Manhattan, New York city, in the county of New York and York, have invented a certain new and useful Process of Making Rubber Articles, of which-the following is a specification.

This invention relates to rubber or flexible tires for automobiles and other vehicles; and its object is to produce a tire which shall be serted in the tire, they are in a vulcanizable condition and each contains a small quantity of a gas-producing agent, such as ammonium carbonate. lVhen they are put into the tire, the latter is also uncured or vulcanizable. The tire is completely filled with the bullets, which are preferably spherical in form, so that very little space is left between them. Then the tire is spliced, as usual, and vulcanized in a, mold in the usual manner, the heat also serving to vulcanize the bullets and to expand the volatile substance in the bullets. The latter are thus distended so as to fill completely the tire..that is, so that there are substantially no interstices between'the bullets, .the latter being pressed by one another into polyhedral and other forms. Thus each bullet has a permanent charge of gas under high compression and the conditions are such that there is practically no loss by leakage or otherwise. If the tire is punctured at any point, only one bullet is penetrated, and the reduction in the resiliency of the tire is hence wholly imperceptible. In fact, the tiremay suffer scores of punctures and still retain a high and satisfactory degree of resiliency. 'I also provide means whereby loss occasioned by the punctured and collapsed bullets may be made State of New valve.

These bullets are small balls and are. made of a'good quality of rubber. When in-- good, and other featuresand advantages will hereinafter appear.

In the accompanying drawings, Figure l is a cross-section of a hose-pipe tire uncured or ready for vulcanizing and showing a mass of vulcanizable hollow soft-rubber bullets filling the tire, some of the bullets shown in section. Fig. 2 is a cross-section of the Fig. 1 tire after the latter is vulcanized. Fig. 3 is a cross-section similar to Fig. 1, but showing a vulcanizable detachable inner tube containing vulcanizable bullets. Fig. 4 shows a fragment of the Fig. 1 or Fig. 3 tire, showing an opening therein large enough for introduction of a bullet, said opening provided with a cap and the latter having also an inflation Fig. 5 shows the Fig. 3 article as vulcanized and inclosed in a cover or tubular rubber tread. Fig. 6 shows in section one of the cups from which the bullets are formed as seen at Fig. 1. Fig. 7 shows a variety of polyhedral forms assumed by the bullets as they are compacted together in the process of vulcanization. Fig. 8 shows a pair of cups. Fig. 9 shows a bullet with an outside layer or ply of fabric forminga reinforcingjacket. Fig. 10 shows a cup having a lining of fabric. Fig. 11 shows a solid bullet of soft rubber.

'. In making a tire I first produce a large quantity of vulcanizable soft-rubber bullets 1. These may consist of cups 2, 3, to whose edge is applied cement 4. The cups are unvulcanized, so that when they are placed together to form a bullet the latter when subjected to vulcanizing heat becomes a hermet ically-sealed hollow soft-rubber body. The cups, however, may be partially cured after they are cemented together and before inserting within the tire, so as to set the joints or seams in the bullets. I insert within the cups before joining them small quantities of any suitable gas-producing agent 5, so that when the bullets'are subjected to the heat of final vulcanization the soda is caused to assume a gaseous form and expand the ball much beyond its normal capacity. Each cup'may be formed with a reinforcing ply or layer 6 of fibrous material, which maybe applied to the outside of the ball, as at 7, Fig. 9, or it may be both inserted, as at Fig. 6, or placed IOC outside, as at Fig. 9, and the outside layer may consist of windings of thread instead of weavings. It is also apparent that the reinforcing layer may be applied to the'inside of the cups, as at 8, Fig. 10.

An unvulcanized' hose-pipe tire 9 is formed in the usual manner and may have the usual windings or plies of duck. unvulcaniz'ed hose-pipe tire I insert hundreds of the rubber bullets 1, each of which is of far less diameter than the inside diameter of the tire, so that at any point in the tire the bullets will be found to lie or rest one upon another across the tire. I also preferably introduce into the tire a mass of loose or free powdered graphite 11' and a quantity of bicarbonate of soda 1 2. The tire thus prepared is placed within a suitable mold and subjected to vulcanizing or without ridges.

tended to be spread-evenly over the bullets.

- bullet.

heat. Both the bullets and the tubular tire are thereby completely vulcanized. The soda 5 Within the bullets is changed to gaseous form and expands them much beyond their normal. capacity, and they become closely. compacted together, each being expanded as far as possible consistently with the pressure of the surrounding bullets, so that substantially the entire interior of the tube 9 is filled. The bullets are pressed by '-one another into irregular polyhedral shapes,

as at Figs. 2, 5 and 7, and the gas in them is in a state of highcompression. The loose gas-producing agent 12 in the tube 9 is also expanded into gaseous form and insures that at the completion of the molding. operation the inside surface of the tube shall be smooth The graphite 11 is in and the inside of the tire, so as to avoid'cha'fing of the parts upon one another as the tire isflexed in use. The graphite is not changed by the heat of vulcanizing.

When the tire is in use, it possesses equal or superior resiliency to the ordinary pneumatic tire, and, ifdesired, the degree of com. pression of the gas within the bullets or polyhedral members may be far greater than practicable or convenient to attain in pneumatic tires.

Should puncture occur at any point in the tire, it will be, seen' that only the bullet or polyhedral member which is immediately at the point of puncture is penetrated or cut.

Such bullet of course loses its charge of gas and collapses; but no appreciable effect is produced upon the tireas a whole because the neighboring bullets all immediately expand and fill up the space of the punctured The loss of resiliency in the entire tube is therefore proportional to the ratio which the space occupied by the bullet bears to. the entire s ace in the tube, and as there are preferably hundreds of bullets in'the tube it will be' seen that a puncture at any po nt means a reduction of only asmall' fraction of Within this enoy due to numerous punctures.

one per cent. of the pressure in the tube.-

Thus the the may continue in use and may receive from time to time many punctures without detracting sensibly from its resiliency'or usefulness, and in the natural course of events it Wlll wear out before it receives enough punctures to render it undesirable. The rubber used for the bullets is of a stock which is very dense or solidthat is, a 00111- .pressed stock is used such that gas cannot:

leak through it. The rate of leakage through walls of the bullets would in any event be very slight because each bullet is surrounded on all sides by a wall of rubber which tends to prevent the leakage,lthe' pressure between the walls of each bullet and the adjoining walls being very great.' Moreover, owing to the initial high pressure within the bullets there may be a substantial leakage of .gas therefrom without reducing the resiliency of the tire to an undesirable point, and as such leakage would necessarily require a long time it follows that the life of the tire will not be reduced by mere leakage.

Preferably I provide the tireor tube with an opening 15 large enough to receive a bullet 1, said openingbeing in the form of a tube 16, normally closed by a screw-cap 17.

Through this opening may beintroduced solid soft-rubber bullets 18 or fabric-jacket balls, such as seen at Fig. 9, the latter 0on taining gas in a state of high compression. As many of the balls, as seen at Fig. 9 or Fig. 11, may be forced into the tube 9 through the opening 15 as is desired from time to time to compensate for lossof pressure and resili- The tube 16 may be too small to accommodate the bullets 1, as it is only necessary for the tube to accommodate small bullets, any required I number of which may be forced into the tube.

The invention applies not only to hosepipe tires, (seen at Figs. 1 and 2,) but also to double-tube" or detachable tires. is seen an-inner tube 19 of soft rubber which is filled with balls- 1 and is otherwise similar.

to the tubes seen at Fig. 1. This inner tube, with its contained bullets, may be cured in in Fig. 3

the manner already described, and in order -to withstand the expanding pressure of the bullets the tube may be provided With one or more reinforcing layers or windings of duck 20 or any other suitable'material. The tube may then be placed within the usual cover or tubular tread 21, having usual flanges 21 for attachment to a rim. The devices16 and 17 maybe .used upon the inner tube 19 for the purpose already described, and in this case the cap 17 may be provided with an ordinary inflation-valve 22, having 'the usual cap 23,

which will be useful for infl ationof the inner tube from timeto time. This is an advan-, tage, because even if the cover and inner'tube are punctured there can escape only a small quantity of air, since the tube is almost entirely filled with the bullets-or polyhedral bodies, and these on account of their contained compressed gas prevent the the from unduly deflating, and hence insure against accident. Hollow rubber balls may be used in this connection that have check-valves on the inside and are made of a simple compound of rubber or with a compound of ruber and cotton or other fabric to give the balls strength. These check-valve balls may be inserted in collapsed condition through the opening 15 and owing to their inherent sprin iness or tendency to assume their normal s ape may draw in air from time to time as permitted by the neighboring balls orbullets, so that if many bullets become deflated their room will be taken up by these selfexpanding balls, whose interior valves will prevent loss of air at any time. Another method of replenishing the tire or tube is to insert a collapsed soft-rubber bullet, the latter provided with a hollow stem through which it'may be inflated after the bullet is inserted in the tire. This bullet maybe inflated to considerable extent and then the stem sealed in any suitable manner and as many bullets of this kind introduced and expanded and sealed as arefound necessary.

All of the bullets may be made and vulcanized, each containing gas under pressure, and then inserted in the unvulcanized tube. In case the bulletswhen inserted in' the tube are unvulcanized or partially vulcanized the amount of sulfur put in them or compounded with the rubber of which they are made will be of such quantity that their vulcanization will be completed when the tire itself is com letely molded or vulcanized. In other worr s, the bullets would be neither undercured or overcured.

Variations may be resorted to within the scope of my invention, and portions of my improvements may be used without others.

Having thus described my invention, I claim:

1. The process of making a rubber vehicle tire, consisting in placing hollow bodies of yielding m aterial, each containing a gas producing agent, into an unvulcanized rubber tire or cover, and then subjecting the whole to heat, so as to vulcanize said cover and expand the producing agent in said. bodies.

2. The process of making a rubber vehicle tire, consisting in placing hollow bodies of unvulcanized rubber, each containing a gas producing agent, into an unvulcanized rubber tire or cover, and then subjecting the whole to heat, so as to vulcanize the tire and said hollow bodies, and expand the volatile substance in said bodies.

3. The process of making a rubber vehicle- .tire, consisting in placing hollow'expansible bodies or unvulcamzed rubber, each containtire.

4. Theprocess of making a rubber vehicle tire, consisting in placing hollow bodies of yielding material, each containing a gas producing agent, into an unvulcanized rubber tire or cover, and then subjecting the whole to heat, so as to vulcanize said cover, and expand the gas producing agents in said bodies, the gas roducing agents being originally introduced in such quantities in said bodies that at the completion of the vulcanizing operation, each body contains gas at a very high pressure so that the tire is highly distended thereby. 4

5. The process of making a flexible vehicle tire, consisting in placing hollow bodies of unvulcanized rubber, each containing a gas producing agent, into a tire or cover, and then subjecting the same to heat suflicient to vulcanize the bodies and volatilize the gas producing agent.

'6. The process of inaking a flexible vehlcle tire, consisting in placing hollow expansible bodies of unvulcanized rubber, each containing a gas producing agent, into a flexible tire or cover, and then subjecting the same to heat so as to vulcanize said hollow bodies, and expand the latter sufficiently to cause them completely to fill the tire, the gas producing agent being originally introduced in such quantities in said bodies that at the completion of the vulcanizing operation, each body contains gas at a very high pressure so that the tire is highly distended thereby.

7. The process of producing a distended rubber body, consisting in inclosing therein small bodies of rubber, each containing a gas producing agent, and then subjecting the same to heat.

8. The process of making a hose-pipe vehicle tire consisting in introducing a mass of hollow balls of uncured rubber, each containing a charge of gas producing agent, then splicing the tire and subjecting the whole to heat so as to cure the tire and the balls, and

to cause the gas producing agent to expand.

& $52 ,130

form balls, partially curing the balls so as to 12.v The process of making a distended tire,

set the joints, filling a tire or cover With the consisting in filling an uncured tire or cover balls, and then subjecting the whole to heat. with partly cured rubber bullets, each con- 11. The process of forming a flexible tire, taining a gas-producing agent, and completconsisting in introducing into a, tire or cover ing their vulcanization sin'lultaneously with I 5 a mass of vulcanizable soft rubber bullets tol the vulcanization of the tire itself.

gether with a mass of loose or free powdered I FRANK A. MAGOWAN.

graphite, each bullet containing a gas pro- VVitnessest V ducing agent, and then subjecting thewhole B. C. STICKNEY,

10 to heat. KITTIE FRANKFURT. 

